Froth-flotation concentration of ores



Patented. 'Aug. 6, 19 29.

umrsofgs'rArss PATENT-OFFICE.

- "R'ATION NORTH AMERICAN- or MARYLAND. L

CORPORATION, OF. NEW YORK, N. Y A. CORPORATION IBO'IH-FLOTATION CONCENTRATION OF ORES,

1T0 Drawing. 'Application filed *ugust 4, 1926, Serial No. 127,180, and in Great Britain August 12, 1925.

This invention relates to the froth-flotation concentration of ores,and is herein illustrated as applied to the differential flotation of lead-zinc ores, for the collection of a lead 5 concentrate with the separate collection of a zinc concentrate, if desired.

According to the present invention a froth concentrate is separated by the aid of a flotation agent which is mainly composed of a soluble mineral-frothing agent, such as .cre-

sylic acid or steam distilled pine oil, thereby floating the desired value, nearly free from any other normally floatable .material. A modifying agent, such as a cyanide, maybe used in addition to this flotation agent to in- -hibit the flotation of the other material, thus for example facilitating the separation of lead from zinc. The flotation agent used for producing a second froth may also be mainly composed of a soluble mineral-frothing agent,

' such as cresylic acid, or steam distilled pine oil; and other agents may be used therewith.

In this waya large recovery of an exceedingly rich' lead concentrate may often be effected. Any iron present may be largely kept out of both the concentrates. Example '1.- Low grade ore fi'om Keno Hill, Alaska, was made into a pulp with water and agitated with 0.15 pounds potassium cyanide, 0.10 pounds potassium xanthate, and 0.20 pounds cresylic acid, all per ton of ore, and a lead-bearing froth separated. The results are. shown in the following table, from which it will be seen that a large recovery of the lead was effected in an exceedingly rich concentrate, and that there was substantially no concentration of the zinc with the lead.

1 Assays Recoveries 402 Wt. Pb. Zn. Pb. Zn.

Heads 100. 4. 86 3. 5 100. 100. Pb. conc 6.4 73.0 3.6 96.2 6.6 Pb. teiL 93.6 .2 3.5 3.8 98.4

Example 2.-A pulp of an iron-bearing lead-zinc ore from Mexico was agitated wit 0.7 pounds of potassium xanthate, and 0.10 pounds cresylic acid, both per ton of ore to yield a lead concentrate, and then' further agitated with 4 pounds of lime, 1.2 pounds copper sulphate, 0.2 pounds of potassium xanthate, and 0.15 pounds ofsteam distilled pine oil, all per ton of ore, and a zinc concenv Assays s are-ow 2-2 5 \IQOQ Example 3.A pulp of Nevada lead-zinc ore, carrying some silverwas similarly agit-ated with the sameagents in the same proport on, to yield a lead concentrate and a zinc concentrate, the results being shown in the following table:

* Assays Ag. oz Pb. Zn.

Hesds 10. 8 11. Pb. cone. 25. 9 83. 6 9. Zn. cone....'... 6. 7 1. 2 50. Tails 10 0. 4 1.

The indicated recovery. of the lead in the lead concentrate was 95.5%.

Ewample 4.A pulp of ore from Federal Morning Mine ore was agitated with P0- tassium cyanide 0.15 pounds, potassium xanthate 0.05 pounds, and cresylic acid 0.1 pound,

all per ton of ore, and a lead-bearin froth.

t I Assays Pb. Zn. Fe.

11. 5 0.0 21. 04.4 e. e o.

9.5 50.0 a no 4.0 25.6 2.4 .4 a

Having thus described certain embodiments of my invention what is claimed is:

1. The process of concentrating an ore containing a floatablevalue and another normally floatable material which consists in,

NIOIAO f agitating a pulp of the ore with a xanthate and with a flotation agent mainly composed of soluble mineral-frothing agent, to yield a=' froth rich in the floatable value, separating the froth, further agitating with the addition of a further agent adapted to facilitate the floating of the other normally floatable marating the froth, further agitating with the addition of a further agent adapted-to facili-' taterthe floating of the zinc so as to yield a froth rich in zinc, and separating the froth.

'3. A process of concentrating a lead-zinc ore which consists in agitating a pulp of the ore with a Xanthate and cresylic acid to yield a froth rich in lead, separating the froth, further agitating with the addition of pine oil to yield a froth rich in zinc, and separating the froth.

In testimony whereof, I have afiixed my,

signature to this specification.

CARL PIERCE LEWIS. 

